Samsung RS21KLMR diagnosis and trouble shooting

Check the exchange of fuse and

disconnection cause.

- Check the connections of main PCB.

- Check the connections between upper hinge and CABI-door.

- Check the connections between door and panel PCB.

11. Diagnostics

11-1) If power is not ON

At the power of main PCB, the 1 15V power and a high-voltage over DC 170V occur. Please take care of yourself on repair and measurement.

Is 230V AC fuse down?

Is power 230V

both terminals of CN10?

Is fuse on main PCB down?

Is DC 320V impressed to both

terminals of BD1?

Top S/W 233Y

Is the voltage impressed DC 5.8V

between C and S ?

Is 12V impressed to both

terminals of C102?

Is the load such as relay normal?

Is normal the load, such as

relay?

Is there any PCB soldering, short or broken?

Normal

Start

To check the main PCB, please apply descriptions of operation and references in the manual.

YES

Check the assembly and connection of

electric wires.

Exchange fuse

250V/ 2A?

YES

Check the PCB pattern and replace BD1.

Replace PCB assembly.

1) Replace D104 (D5S6M).

2) Replace PCB assembly.

Replace REG1(KA7805)

1) Check the assembly of electric wires and troubleshoot.

2) Replace the panel PCB.

1) Replace the corresponding relay.

2) Check lead wire for contact.

Caution!

Diagnostics

1 1-2) If the compressor and cooling fan motor don’t work normally

Apply Ref.4

Did 5 min pass after COMP. OFF?

Start

Check after a lapse of 5 min.

Did buzzer sound on forced operation?

(Check certainly after forced start.)

Exchange MICOM and PCB.

Exchange and repair IC03.

(ULN2803)

Does compressor work

with forced operation?

Is MICOM No.18 High?(5V)

Open and repair the

connection.

Troubleshoot the

sensor and Exchange

PCB.

Is the voltage of IC03 pin No. 14 between 0-1V?

Open and troubleshoot the

connection.

Is COMP relay normal?

Exchange or troubleshoot

COMP relay.

Apply Ref. 2

Is the contact of connector CN70 normal?

Insert connector completely?

Is COMP assembly normal?

Exchange and repair COMP.

assembly.

Normal

YES

Is freezer sensor normal?

Is the temp. sense

of main PCB Normal?

Diagnostics

11-3) If defrost function

Is F, R defrosting sensor by

self-diagnosis normal?

Start

Exchange and troubleshoot the

corresponding sensor.

󳢮 See Ref. 3: ‘Check load’ in the manual.

󳢮 Make decision on the basis of ref. 4 and

6 in the manual.

󳢮 See test function in the manual.

󳢮 Recheck the corresponding sensor for

an error if it fails in return.

󳢮 See ‘Load Drive Circuit section’ and Ref. 2: How to check failure of relay.

Is F, R Room defrosting heater normal?

Check temp. fuse,

breaking of heater wire, contact of

wire and so on.

Is temp. of the defrosting

sensor below 23℉?

Run forced operation for a

specified period.

Repair the connection terminal.

Perform forced defrosting for F and

R room at a time.

Normal

Check temp. fuse, breaking of heater wire,

contact of wire, and so on.

Exchange or troubleshoot the failure relay or

exchange PCB ass’y.

Is power applied to the

respective defrosting heaters?

Does the system

return to cooling operation after heating

for a specified period of time?

Recheck the connection

terminal in Main PCB

YES

If temp. of F, R defrosting sensor by the working of heater are over 10℃, 17℃

Reference

Diagnostics

1 1-4) If there is a trouble with self-diagnosis

1) If the ambient sensor has trouble

No trouble with PCB and temperature sensor.

Recheck the contact failure of connector.

YES

2) If the temperature sensor of F and R room has trouble

󳢮 See Ref. 4 (descriptions of

circuit operation, and how to check temperature sensor in the manual.)

- Error of sensor can be seen on the front display of refrigerator. If power is impressed to refrigerator first, an failure of sensor is found. The refrigerator will stop working and display(blink) the region of trouble-occurred sensor repetitively.

- Even if sensor has failure during the operation, the refrigerator will not stop working but can run the normal cooling operation because of being operated in the Emergency Operation mode. Therefore you’ re requested to use how to check self-diagnosis in the manual.

A bad contact or connector missing?

Was the Main

– PCB connector(CN31) inserted

correctly?

Is the ambient temperature

sensor normal?

Is the input of voltage to

MICOM pin No. 63 normal?

Start

Exchange the temperature sensor.

Check the iced solder and

short of main-PCB.

YES

󳢮 See Ref.4 (descriptions of

circuit operation, and how to check temperature sensor in the manual.)

󳢮 For sensor resistance per

temperature, make use of the resistance values from Ref. 4 and 5.

Exchange the temperature sensor.

Is the unit of

Fridge’s temperature

sensor normal?

Was the Main – PCB

connector(CN30) inserted

correctly?

Is the sequence of

insertion of connector(CN30) wire identical to

the circuit diagram?

Is the input voltage to

MICOM pin No. 59 normal?

Start

Troubleshoot a bad contact or missing of

connector.

Check if the iced solder of main PCB is

short.

Modify the wrong configuration of connector wire -in case of being not inserted or incorrectly inserted - to be coincided with the circuit diagram.

No trouble with PCB and temperature sensor. Recheck the connector for an error of contact.

󳢮 Freezer door MICOM No. 43,

Fridge door MICOM No. 44 – Regular voltage are 5V to Open :

0V to Close.

󳢮 Separate the door S/W and

check if the measured value of unit is changed from 0 to∞Ω according to S/W ON/OFF.

1) If “Ding-Dong” sounds continuously

Isn’t the door opened minutely?

Start

Remove causes after comprehending the conditions of interference by door gasket, food etc.

Isn’t water penetrated

into the door S/W?

Exchange the door S/W.

Is the input voltage of

main No. 43 and 44 changed at door-open,

door-close?

Troubleshoot the breaking of wire and

bad door S/W.

Main PCB and door S/W are normal.

Yes

YES

Connector not inserted. Troubleshoot

poor contact.

Exchange the door S/W.

YES

Is the state of inserted connector

(CN30)being normal?

YES

Is the door S/W self-unit normal?

YES

2) If “Beep” sounds continuously

Didn’t you

select forced operation and forced

defrosting?

Start

Release the forced operation and

forced defrosting functions, or turn ON

again after power OFF.

Do buzzer

still sound after power-on

again?

Main-PCB is normal

Check if there is any short parts due to

foreign matters and the test

jumper part in the main-PCB.

Selected

YES

Diagnostics

11-5) If alarm sound

Diagnostics

3) Without sound of buzzer operation

Does it sound

‘Ding-Dong’if you press a button

on front panel?

Start

Main PCB is normal; buzzer normal.

Check the panel PCB with the reference of ‘how to check panel display’.

Buzzer is broken – replace it.

Does it make a sound of ‘door-open’ alarm

when you are opening the door of freezer or fridge

more than 2 min?

Is the bent or go-out of the buzzer

in the main PCB?

The main PCB and buzzer are normal

YES

Replace the main PCB.

(failure of MICOM)

Are signals coming

out of MICOM No. 21 in a 1-sec cycle

after the Forced operation?

Is signal of Q801

Base ouputted with 1 sec. intervals

in the condition above?

Did lead of a

component fall on the vibration plate

of buzzer?

Check the state of pattern connection

between MICOM No.21 and Q801.

(Check Open/Short)

Poor buzzer is broken down or

replace the buzzer.

YES

󳢮 Refer the description of

Test function in the manual for the Forced operation.

Diagnostics

11-6) If the panel PCB is not working normally:

1) Where lighting of the panel PCB is disabled, or only some lamps are disabled.

2) Where the Panel PCB key isn’t selected:

- The basic check way : If you is troubleshooting in the basic check method, then

Is the connector

of upper hinge cover inserted

normally?

Start

Reinsert the connector. Troubleshoot

a poor contact.

Is the main PCB

connector(CN50) inserted

normally?

Reinsert the connector in the main

PCB.

Is the connector of

door panel PCB connector inserted

normally?

Reinsert the connector. Troubleshoot

a poor contact.

1. Check the door wire of freezer – the disconnection of wire, short between wires.

2. Check the CABI wire of freezer – the disconnection of wire, short between wires.

3. Check the panel lighting circuit section within the main PCB for short open.

1. Check the door wire of freezer – check the breaking of wire, short between wires.

2. Check the CABI wire of freezer – check the breaking of wire, short between wires.

3. Check for Short/Open of the Panel Lighting Circuit section in the main PCB.

YES

Panel PCB itself has trouble.

YES

Is lighting operated

normally when the exchange of panel

PCB?

Recheck after the release of locking function.

YES

Is the locking lamp lit on?

YES

Reassemble the PCB ass’y/Enforce the cancellation of pressed keys.

Aren’t a key or more buttons

pressed continuously?

YES

Reassemble the PCB ass’y/Enforce the cancellation of pressed keys.

Operated by separation

Isn’t the PCB system

still operated by seperating of the

mechanism?

Panel PCB has trouble for itself.

YES

Is lighting

operated normally in the exchange

of panel-PCB?

YES

1. Replace the main PCB.

2. Check the short wires of CoolSelect Zone

panel.

Is a periodic

wave form outputted from the main

PCB IC9?

󳢮 See Ref. 1: ‘View of the

connection cabinet-door for the wire assembly’ in the manual.

󳢮Refer to the description of

circuit operation in the manual 10-6) Key scan and display Circuit selection’s, and measure the wave pattern.(page 40)

+ 14 hidden pages